When you hit a key on your keyboard, you want it to go to the console you are working on and application(s) running on that console should get the event delivered. Other applications running on other consoles should not get the event (for obvious security reasons). When you want to switch to another physical (dual-head) or virtual (also known as VTs) console, you press a key combination to switch and then want now your chars to be sent to the right console. In other words, you need the system manages the focus for you in a convenient, deterministic and safe manner.

These connections are at the same time dynamic and static. Static because the relationship between display and input instances is predefined. Dynamic because you can register any KgiInput (ps/2, usb mouse or keyboards) or KgiDisplay to the KgiFocus.

So what is predifined relationship? Let's have a look at the following:

It presents the case of 2 keyboards (represented by 2 focuses) for which one has 3 screens. Each focus can reach 12 consoles (typically what you get with a PC keyboard with F1..F12). Focus 1 is totally linked to display 2 (1 keyboard + 1 screen wired config) and focus 1 can either control consoles 0 and 1 through display 0 and others through display 1. It means that with focus 0, when you hit ALT+F1 you edit commands on display 0, ALT-F3 : you edit on display 1, ALT-F1 you change VT on display 0 and ALT-F4 to ALT-F12 : you switch to VTs on display 1.